SHOTGUN - Rick Smith takes the snap. [Pass Defense - long cover]
The defense is starting to get pressure on Smith. Smith throws to Rosa behind the line of scrimmage (very short). Rosa pulls in the catch.
Robert Torres trips up Rosa to bring him down at the GC 30. 4-yard gain.

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Pass defense is in long cover and the SS should be covering long/deep. Yet he is the first one to make contact when the receiver is only 4 yards downfield. It seems like there are way too many people in the target zone in very short and short if the safety is also considered to be there even if his coverage is long.

SHOTGUN - Rick Smith takes the snap. [Pass Defense - long cover]
The defense is starting to get pressure on Smith. Smith can't get the pass off to Delgado at the L 31 (deep).
Smith starts to scramble.
Smith is tackled by Robert Torres at the GC 36. 3 yards on the play.

Pass defense is in long cover and the SS should be covering long/deep. The SS is the one who stops the scramble at only 3 yards. It seems unrealistic for a player covering deep to be able to stop a scramble at only 3 yards. It seems like the safeties have way too much presence all over the field if they're able to cover deep and stop scrambles for short gains.

SHOTGUN - Rick Smith takes the snap. [Pass Defense - long cover]
Smith rolls out of the pocket.
Smith throws to Goodman at the L 5 (deep). Goodman pulls in the catch.
Goodman breaks a tackle by Edward Rush and runs into the end zone. 40 yards gain.

Another example of confusing coverage. Here, CB1 is covering WR4. Who should be covering WR4, an LB? Who is covering WR1 and WR2?

SHOTGUN - Rick Smith takes the snap. [Rush Defense - BLITZ: McCoy - long cover]
Smith doesn't see the wide open Goodman at the CUW 24 (deep).
Smith throws to Curtis at the GC 47 (long). Curtis pulls in the catch.
Timothy Hunt can't get his hands on Curtis.
Curtis breaks a tackle by Timothy Hunt and runs into the end zone. 66 yards gain.

Posted by norbert on 4/24/2013 10:54:00 AM (view original):Where the safety plays is based on cover but is split across several locations with most of his "influence" in the location I posted above with a little bleed over influence in the neighboring locations. Safeties in Long cover will also be active deep.

For instance, if you have 4 WRs going deep, the CBs will cover them and Safeties depending on cover setting. A Long cover setting will set the Safeties to have more influence deep and therefore more coverage, while a Short setting will produce less coverage. This all goes in to feed the chance that the target has more than one defender on him, which in turn will adjust his chance of being open.

There are probably about a dozen things I can think of just to improve the cover logic. The 3.0 engine breaks the plays down into pieces that all go in to feed the next piece. Future updates will probably be focused on one particular piece, like the cover logic. As it stands, the cover logic, I think, does a pretty good job of matching players up based on settings for both offense and defense, as well as comparing ratings to get open with a different mix of ratings depending on the location and defender. There is logic to help prevent a defender from "double dipping" in providing cover in one step and the next, but it only checks the last step, so that could be improved. All in all, even with the improvements I see that could be made, it's a ton more sophisticated than 2.0 and can only get better whereas 2.0 had no good way to improve.

I would like to figure out a way to provide more of this sophistication in the PBP, but I also don't want to bloat the PBP to where it becomes undesirable to read. If there is anything you guys would like to see in particular when it comes to how well a player is covered, let me know and we'll see if we can figure out a way to put it in the PBP that flows well.

In your "For instance", does the safety provide influence over the entire area, i.e. all receivers going deep? If 4 receivers go on streaks, will one safety provide coverage influence on all of them? If so, this seems a little unrealistic to expect them to have influence from sideline to sideline. If not, how is it determined which receivers are more/less heavily influenced?

For which CB is on which WR, it currently does not try to line up slots. Much as there isn't a right/left designation, I didn't want to add in some functionality that you have no control over. Of course, all of this can be considered and improved upon, but for the base of 3.0, I decided it would probably be most fair to split chance of coverage amongst all the eligible defenders. When looking at all the possible ways of handling coverage assignments, this seemed like the most fair way to handle it short of setting which slot covers which slot from the defensive settings end which would add a whole new level of complexity to the settings that we probably do not want. So for now, if there are 4 WRs and 4 CBs, each CBs cover influence would be split amongst those WRs. Definitely room for improvement in this area, but this seems like the best way to handle it to start out.

I keep talking about influence, so it might help to understand what I mean by that. For receivers, they will be assigned a certain amount of influence for each location (VS, SH, M, L, D) that adds up to 1.0 (or 100%). This is based on the slot pass distributions, so if a WR was set to 10/20/40/40/50, his influence would be set to .06/.12/.25/.25/.32. Note that this is different than his chance to be the target in each zone. Basically these influence numbers represent the receivers chance to be in any given zone on any given play. Of course, a player can't be in EVERY location at any given time, but this would be similar to what pattern you would see over several plays of the same type. To determine the defenders influences, you would add up all of the WRs influence in a particular location and then spread it amongst the CBs, for instance. LBs get their influences from RB/TE influences. Safeties get influences set directly from the cover setting. What this all gives us is a way to pick a defender(s) in a certain location after determining the target location and target receiver. Once we have the target receiver and defender(s) we can determine how open the target is. This also means we can tell how congested a location is based on how much total influence is in the location. For instance, if all WRs are running deep, it is more likely there are more defenders deep as well. If there is more defensive influence in the location, typically due to S cover or having more defenders than targets, it will give the defense an advantage in cover. So influence is an important part of the cover logic.

Another important part to know - as you show in several examples - is that this is just the player's influence for COVER. Once the ball is thrown and the receiver is running, defenders will move towards the ball carrier. The chance they get to the ball carrier in a certain location is dependent on their initial cover influence but will change as the ball moves. So a S that was set to Long cover currently has some influence in the medium location and if the ball is caught VS (behind the line), he will probably be able to react to try to take part in the tackle attempt by the time the ball carrier gets into the short location. Now if the ball was caught in the short area instead of the very short area, there's actually less time for him to react to be part of the play, so he most likely would not be tackling a receiver for 4 yards if the receiver caught the ball in that area.

The nice part is that most of this is isolated, so we can adjust those initial cover influences and also adjust how well a player would react to take part in the tackle after the catch. Most of this is kept pretty simple right now with ratings mixed in where I can, but this is another area that could be improved. I could definitely see GI play a greater part in the S moving up from Long cover to tackle a guy in the short location than what it is now, but I'd like to get the base pretty solid before introducing more complexity. It's already difficult enough to balance all the moving parts as it is. But definitely things we can improve on later.

Oh, as far as what happens when there are 4 WRs deep and 1 S, I don't think I addressed that. Basically when looking at the cover the defense has in a location, we look at those influence numbers and can look at the single value split across receivers. So the defensive influence advantage might be 1.5 with 2 WRs and 1.25 with 4 WRs in the case with 1 S in the area. What this tells the engine is that there is less chance the S is covering the target when there are 4 WRs in the location. Again, lots of possibilities to work player talent into this.

For SS stopping the scramble in the short area, this is the same case as the receiver stopped short. This might be an indication that the code that determines which players are active in each zone could be adjusted.

One thing about this is that this is actually one place where the GI and IQ of the player contribute to the play. What is this SS's GI and IQ? A higher GI and IQ will give a higher chance that a player can adjust to the play on the field and would produce a higher chance that a SS in long cover would move up to stop a player in the short area (1-6 yards). Of course, this is also subject to adjustment if we feel these players should not be able to move up that quickly and I agree it's a little sketchy to see a player in long cover react fast enough to move to make a tackle short.

I keep talking about influence, so it might help to understand what I mean by that. For receivers, they will be assigned a certain amount of influence for each location (VS, SH, M, L, D) that adds up to 1.0 (or 100%). This is based on the slot pass distributions, so if a WR was set to 10/20/40/40/50, his influence would be set to .06/.12/.25/.25/.32. Note that this is different than his chance to be the target in each zone. Basically these influence numbers represent the receivers chance to be in any given zone on any given play. Of course, a player can't be in EVERY location at any given time, but this would be similar to what pattern you would see over several plays of the same type. To determine the defenders influences, you would add up all of the WRs influence in a particular location and then spread it amongst the CBs, for instance. LBs get their influences from RB/TE influences. Safeties get influences set directly from the cover setting. What this all gives us is a way to pick a defender(s) in a certain location after determining the target location and target receiver. Once we have the target receiver and defender(s) we can determine how open the target is. This also means we can tell how congested a location is based on how much total influence is in the location. For instance, if all WRs are running deep, it is more likely there are more defenders deep as well. If there is more defensive influence in the location, typically due to S cover or having more defenders than targets, it will give the defense an advantage in cover. So influence is an important part of the cover logic.

I think this is the problem. In some of my examples, there are only 2 CBs covering 4 WRs. Any QB with decent GI should be able to dissect that defense with that kind of numerical advantage. Shouldn't the CBs influence be halved at this point? This should be part of the formation advantage IMO. Conversely, if there is only one WR and 2 CBs, shouldn't the influence be doubled?

Another important part to know - as you show in several examples - is that this is just the player's influence for COVER. Once the ball is thrown and the receiver is running, defenders will move towards the ball carrier. The chance they get to the ball carrier in a certain location is dependent on their initial cover influence but will change as the ball moves. So a S that was set to Long cover currently has some influence in the medium location and if the ball is caught VS (behind the line), he will probably be able to react to try to take part in the tackle attempt by the time the ball carrier gets into the short location. Now if the ball was caught in the short area instead of the very short area, there's actually less time for him to react to be part of the play, so he most likely would not be tackling a receiver for 4 yards if the receiver caught the ball in that area.

A S set to long cover has some influence on Medium, but I expect him to physically be long. I think it's unrealistic to expect him to physically be able to cover long and make a play short on the same play. I don't think the argument you make makes much sense. The safety may have less time to react to a pass in the short area, but he also has less space to close before reaching the ballcarrier compared to very short. I also think if he's playing short, he should have no influence long. So if a receiver(s) go long or deep, the safeties are out of the equation.

SHOTGUN - Rick Smith takes the snap. [Pass Defense - BLITZ: Moore - long cover]
The defense is starting to get pressure on Smith. Smith throws to the wide open Goodman at the L 14 (deep). Pass is off the mark. Incomplete.

Missing wide open receivers seems pretty common. Should we ratchet the completion percentage up when they are wide open and turn it down when they are covered/well covered?

SHOTGUN - Rick Smith takes the snap. [Pass Defense - long cover]
The defense is starting to get pressure on Smith. Curtis is covered at the GC 34 (short).
The defense has heavy pressure on Smith. Goodman is covered at the GC 33 (short).
Smith throws to Delgado at the GC 31 (short). Pass is just out of the reach of Delgado. Incomplete.

Here is an example of how I think coverage is unrealistically strong. The QB looks at 3 WRs short. There are only 2 CBs. The safeties are long so should have little to no influence. Yet two CBs are able to cover 4 WRs (all 4 WRs are short on this particular play). Even if LBs are in on the coverage, and LB/WR matchup heavily favors the WR so he should be open.

SHOTGUN - Rick Smith takes the snap. [Pass Defense - long cover]
The defense has heavy pressure on Smith. Goodman is covered at the 50 (short).
Rosa is covered at the L 47 (short).
Smith throws to Goodman at the 50 (short). Goodman pulls in the catch.
Goodman is brought down by Edward Rush on a strong tackle at the 50. 2 yards on the play.

Here is an example of a safety covering long but still making the play short even though the pass was in the short range and not the very short range. This doesn't seem to show that the WR is getting to medium before the safety can reach him.

When short on the WR/CB match up and LBs have no one to cover, LBs will try to cover WRs. I may have to adjust their effectiveness but essentially it is looking at their ratings on how well they actually cover the players. Theoretically, with the mix of ratings being different for covering further down the field versus short, the LBs should have a natural disadvantage in covering deep. However, if they are covering a WR short, then the comparison would essentially be the same as covering a RB/TE. Basically, we don't penalize an LB that actually has the skills to cover a WR just because he is covering a WR. Don't forget to add rating comparison in to the check for whether a player is open or not, because even a 1-on-1 match up can result in the receiver being covered.

There really seem to be two concerns here: what players are covering different areas and how does that affect the open result AND players participating in tackle attempts in locations they probably shouldn't be able to get to from their cover locations. Luckily they can be treated pretty independently, and I'll look into this closer over next week.

I think the S moving up and participating in a tackle can be addressed in some minor adjustments, but it requires a lot of testing to make sure it doesn't screw up other parts of the play. It's really just shifting the influence set by the cover for Safeties and then adjusting the logic that determines which players can participate in the play at each location. I would try to limit it to move one location per step, which would mean a S in long cover could meet a receiver in the medium area if he caught the ball in the short area, but would not be able to make a play in that short area.

The second part is to review the logic that determines which players are in cover (and their influence). I think the cover check is pretty decent, but maybe I need to present more detail on what each type of cover actually means and what that cover result means for the rest of the play. Probably some room for improvements there as well once I get more feedback.

I think these are good and focused examples of what will help make this a better engine, and I will always believe there is room for improvement. I think working on some of this might help further define how much game settings will matter and i think that's a good thing.

Posted by slid64er on 4/24/2013 5:53:00 PM (view original):What happens when a ball is "in and out of the hands" of a receiver? This does not show up as a drop. Was the pass bad? If the pass was not bad, why wasn't it caught or ruled a drop?

This is a dropped pass. Is it not showing a drop for the player?

There are basically 4 results of a throw:

off target - receiver has no chance to catch it

reach - receiver has to reach to catch the ball, thrown high, behind, etc. Chance to catch based on receiver ratings. If doesn't catch, is not a drop.

slightly off - fairly easy catch. Still chance to drop based on ratings. Will count as a drop.

on target - easy catch. Chance to drop based on ratings (low hands player may drop). Will count as a drop.

There are basically 3 ways a pass can be incomplete:

QB throws off target (or throws at limit of receivers reach)

Receiver drops the ball

Pass is defensed

All of these should be evident in the PBP. It might make it easier to start adding more tags in the PBP like we did for "throw to ABC 20 (short)", so maybe add a (drop) in the PBP when the pass is actually a drop.